Servomotor



Oct. 12, 1937. c, WU R 2,095,404

SERVOMOTOR Filed Aug. 4, 1936 (a); Wu

Gum/wan;

.10 wherein; s s

Fig. -1 is a." side elevation of a gear motor em.-

. Patented ct. 12,1937

PATENT OFFICE SERVOMOTOR Carl Wnrr, Berlin-Lichterfelde, Germany, assign- -or to Askania-Werke A. G. vormals Central Werkstatt Dess'au und Carl Bamberg-Friedenau, a German company Application August 4, 1936, Serial No. 94,265 In Germany November 30, 1935 y 1 Claim.

inventionrelates-to hydraulic motors such as are employed injet pipe regulators and, among other objects, aims to provide a greatly improved and relatively 'simple' m'otor capable of imparting rotary movement of more or lessthan 360 'to a control shaft. v

Other aims and advantages of the invention will appear in the specificatiomwhen Considered in connection with the a'ccompanying drawing,

bodying' 'the'invention, the cover plate being removed; and

- Fig. 2 is a-vertical sectionalyiew of the motor I 5 shown in'Fi 1.

' In hydraulic or'pneu'matic controls such'as are usually employedin regulators, the servo-motors;

of the oscillatingtype' have' been limited to angular movement of less-than 360 or one-revolution and, in most'c'ase's, .to less'than' 180 In many installations,-ita-is desirable to impart an angular movement ofmore than 360, to a'control shaft -'in response to variations-"in' the-condition impulses. 'I'hi's= -in vention', therefore, provides .a '25 novel typeof servo rrioto'r employing a planetary gear piston, connected to impart rotation through -any angle, up -to several, revolutions to a control Referring particularly tosthe'fdrawingthe il- 30 lustrative embodiment" ofthe {motor is adapted to be driven by differential'ilui'dpressure, created, for example, by a jet pipe relay or delivered from:

, anysuita'ble sourceiinot-yshowni. In.thi s exam- .ple,the motor is-;showr i as vlng;al-,cy1 i n drical- 35 housing orcasjin'gi Ill and ver plate .I I. An

internal ring gear I! i 12 and acts as.ia;piston.-.-

' The interior of the oasing'isdivided into twofluid chambers 1 6 :and I.|- by-,aradlal partition is between. the spur-gear and thering' gear 12 and securedbinjany suitable. mannertolthe' cas I an hw forllustrative' u'r" mg pms 0 n poses cylindrical casing; an internal ring gear .se-

The gears and .partition are -closely fitted in the casing to make the? chambers fluid ti'glita Pre s-" sure fluid-"is 'iauln'iittedto. and discharged from-'the-- I casing. througlrjconduits 20 "-on' ;;opposite sides of and adjacenti tq mepamum T8. The arrangement isisuch" that the planetary gear piston l5 ably secured within the casing and a driven shaft li carries a pinion or spur gear-l4 inftheneenterof the casingmeshing with a planetary or -;,-fl oati ng gear l 5' 40 which,- in turnmeshes. withtheinternalring gear" until it strikes the-partition i8. ,ijl 'fthe-fpressure vi c im i'l e' lfi-is higher than thepressure 'in chamber H, the gear will try to turn clock wise as viewed in Fig. 1. Such movement of this gear is only possible when it drives the spur gear l4 in a counter-clockwise direction because of the I'herefore, the angular movement of the driven shaft 13 may be much greater than 360, depending upon the ratio between the pitch diameters of the ring gear I2 and the spur g'ear M.

From the foregoing description, it will be apparent that motors of this type are very simple in design and-easy to manufacture. Thegears are self-sealing and prevent leakage ,from one chamber to the other.

ential pressure, the more effective is the seal because the pressure is imparted to the intermeshing teeth. This'is a very decided advantage over ';the well known types of servomotors having vanes or blades capable of oscillating through 'less than-360 because the leakage past the vanes prfblades inereases 'as the differential pressure increases. -Moreo,ver,the motors are adapted for many commercial uses and will serve the same purpose as the more complex' reversible rotary motors. They may be made in the form of very use ascontrol motors.

,Obviously, the present invention is not restricted tothe particular embodiment thereof herein shown .and described. Moreover, it is- 'not indispensable 'thatall the features of the invention be used conjointly, since they may be- The greater the differ compact ,units and are, therefore, well adapted for- .employed' advantageously in various combina- What is claimed is: fluid motor comprising,

cured in the casing; a spurgear-mounted'inthe center of theoasing; a shaft .connected to said gear;' a planetary gear acting as aplstonmeshing with said ring gear and said spur gear; a partition dividing said casing intoa pair of fluid "chambers on opposite sides .-of said planetary,-

gear; and fluid conduits communicating with said 

